KR101086397B1 - IP packet error handling apparatus and method using the same, and computer readable medium on which program executing the method is recorded - Google Patents

Abstract

For an IP packet received from at least one transmitting node, when a situation in which a next error is detected more than a predetermined number of times occurs within a first predetermined time from when a previous error is detected, during the second predetermined time with the transmitting node. An error processing apparatus and method for disconnecting communication and a recording medium having recorded thereon a program for executing the method are disclosed. Error processing may also be performed with reference to a cache portion consisting of one or more entries identified by the address of the IP packet where the error was detected. Thus, the network load of the receiving node can be reduced by not transmitting the ICMP packet to the transmitting node suspected of being subjected to malicious manipulation or denial of service attack of the IP packet for the second predetermined time.

Description

IP packet error handling apparatus and method using the same, and computer readable medium on which program executing the method is recorded}

1 is a diagram illustrating a configuration of an IPv6 packet.

2 is a diagram illustrating a configuration of an ICMPv6 message packet.

3 is a flowchart of an error processing method of a conventional IP packet.

4 is a block diagram of an apparatus for processing an error of an IP packet according to an embodiment of the present invention.

5 is a configuration example of an entry constituting a cache unit according to an embodiment of the present invention.

6 is a time flow diagram illustrating an error processing procedure according to an embodiment of the present invention.

7 is a block diagram illustrating an internal configuration of the error processing apparatus of FIG. 4.

8 is a flowchart of an error processing method according to an exemplary embodiment of the present invention.

9 is a flowchart of an error processing method using the error processing apparatus of FIG. 4.

10 is a flowchart illustrating a specific process of an error processing method according to an exemplary embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting and processing an error in an IP (Internet Protocol) packet. In particular, the present invention relates to an ICMP cache for recording information on a field error of an IP packet, and to a network load by disconnecting IP packet communication under a certain condition. The present invention relates to an error handling technique of an IP packet which can reduce the number of times.

ICMP (Internet Control Message Protocol) is a protocol for controlling messages and reporting errors between a sender and a receiver. It is defined in RFC-792 and operates at the network layer of OSI 7 layer with IP. Therefore, when an error occurs in the IP packet received at the receiving end, the ICMP message encapsulated in the original IP packet is retransmitted to the transmitting end, thereby ensuring the reliability of the IP packet by causing the transmitting end to take appropriate measures according to the generated error. do.

On the other hand, given the current trend of Internet growth, early in the next generation, 32-bit addressing schemes in Internet Protocol version 4 (IPv4) can no longer allocate new Internet addresses, and packets for new service types such as audio and video With the demand for differential delivery, Internet Protocol version 6 (IPv6), which uses a 128-bit addressing scheme, has emerged. FIG. 1A illustrates a configuration of an IPv6 packet and FIG. 1B illustrates a header of an IPv6 packet. An IPv6 packet is divided into a base header and a payload. The payload also consists of an extension header and data packets of higher layers such as TCP or UDP packets. The packet header consists of a total of 40 bytes, of which 32 bytes are allocated to IPv6 addresses and the remaining 8 bytes are allocated to six fields. In particular, the Next Header field identifies the type of information that will come to the data field immediately after the basic header. In addition, the extended header includes a next header field for identifying the type of information to come to the data field immediately after the confirmation header and an option field for identifying the type of the extension header.

Internet Control Message Protocol version 6 (ICMPv6) is a multi-purpose protocol for delivering error messages and information messages between nodes implementing IPv6. Version 4), Internet Group Membership Protocol (IGMP), Address Resolution Protocol (ARP), and Reverse ARP (RARP) have been integrated and simplified by removing message types that are rarely used in ICMP.

ICMPv6 messages are sent attached to IPv6 packets, and ICMP messages are identified with a value of 58 in the Next Header field of the IPv6 header. In the following, IPv6 and ICMPv6 will be referred to as IP and ICMP unless otherwise specified.

2A is a format of a general ICMP message packet. An 8-bit type field indicates the type of message. If the most significant bit of the type field is 0, that is, if the value of the type field is 0 to 127, it is an error message. If the most significant bit is 1, it is an information message. For example, the type field value 4 indicates a parameter problem message generated when a problem is found in a field of the basic header or extended header of the IP packet, and the type field values 128 and 129 determine whether the destination node is reachable. An echo request message and an echo reply message, respectively, used to implement a ping.

The 8-bit code field indicates details of the ICMP message determined in the type field. For example, in the case of a parameter error message, subdivided into header field error (code field value = 0), next header not recognized (code field value = 1), and IPv6 option not recognized (code field value = 2) according to the code field value. do.

The 16-bit Checksum field is used to detect errors in ICMP messages and partially errors in IPv6 messages.

The message body depends on the message type determined in the Type field. In the case of a parameter error message, a body is formed as shown in FIG. The pointer field identifies the location where the error was detected in the original message. In addition, by placing the IPv6 packet that caused the generation of the ICMP message after the pointer field, the sender can take an appropriate action on the IPv6 packet in error.

3 is a flowchart illustrating a field error processing method of a conventional IP packet header in which an IP packet is received at a receiving end, an error is detected in each field of the header, and an ICMP message is transmitted to the transmitting end. When the receiving end receives the IP packet (S402), it searches the version field of the basic header of the IP packet to determine whether the IP packet is 6, and if it is not 6, calls an error handling function to create an ICMP message packet. (S410), the created ICMP message packet is transmitted to the transmitting end (S412). In the same manner, it is determined whether the value of each field of the basic header of the IP packet is a recognizable value (S406 and S408), and if it is not a recognizable value, an error handling function is called to create an ICMP message (S414 and S418). In step S416, S420, the created ICMP message packet is transmitted to the transmitting end. At this time, if there is an extended header, error detection is also performed on the next header field, the option field, and the like of the extended header, and the ICMP message packet is transmitted to the transmitting end as described above. In addition, whenever an error such as an Unreachable Destination, a Packet Too Big, and a Time Exceeded is detected, the associated ICMP message packet may be transmitted to the transmitting end.

As described above, conventionally, when an error occurs in a received IP packet, the relevant ICMP message packet is retransmitted to the sender, so that a malicious user enters the network to manipulate the IP packet or denial of service (DoS) attack. If there is a serious problem in the path shared by two or more nodes, there is a problem that it is not easy to avoid.

That is, the ICMP message packet has a much larger capacity than a general IP packet because the ICMP message packet is an IP packet in which an ICMP message is added to the original IP packet. Therefore, retransmitting the ICMP message packet to the transmitter each time for a deliberately manipulated packet may create a serious load on the network and make normal communication impossible.

 Accordingly, it is an object of the present invention to reduce the network load of a receiving node by not transmitting ICMP packets to the transmitting node when the error of the IP packet detected within a predetermined time is continuously exceeded a predetermined number of times.

Further, another object of the present invention is to not transmit an ICMP packet to a transmitting node of a problem IP packet when an error detected within a predetermined time for the IP packets having the same source address occurs more than a predetermined number continuously. By doing so, the network load of the receiving node is reduced and communication efficiency is increased.

In order to achieve the above object, the present invention provides an apparatus for processing an error of IP packets received from at least one transmitting node, comprising: an error detecting unit for detecting an error in the received IP packets and an error detection; For the received IP packets, if a situation in which the next error is detected more than a predetermined number of times occurs within a first predetermined time from when a previous error is detected, during the second predetermined time and the transmitting node of the IP packets in which the error is detected. An IP packet error processing apparatus including an error processing unit for disconnecting communication is provided.

In this case, the error processing unit preferably performs the error processing on IP packets having the same address information among the IP packets in which an error is detected.

In addition, in order to achieve the above object, the present invention provides an apparatus for processing an error of IP packets received from at least one transmitting node, an error detection unit for detecting an error in the received IP packets, Is an IP packet including an error processing unit for disconnecting communication with a transmitting node of the IP packets for which an error is detected for a second predetermined time when an error is detected more than a predetermined number of times during the first predetermined time. Provide an error handling apparatus.

In addition, to achieve the above object, the present invention provides a method for processing an error of IP packets received from at least one transmitting node, comprising the steps of: (a) detecting an error in the received IP packets; (b) For the IP packets for which an error is detected, the transmitting node of the IP packets for which an error is detected when a situation in which the next error is detected exceeds a predetermined number within a first predetermined time from when a previous error is detected. And disconnecting the communication for a second predetermined time.

In this case, step (b) is preferably performed on IP packets having the same address information among the IP packets in which an error is detected.

In addition, when the error is not detected in step (a), (c) may further comprise the step of processing the received IP packets normally.

In addition, the step (b) may include (b1) a first timer field for setting and subtracting the first predetermined time, a second timer field for setting and subtracting the second predetermined time, and the continuous error occurrence situation. At least one entry including an error count field for counting a number and an address information field for indicating address information of an IP packet in which an error is detected, wherein IP packets having the same address information correspond to the same entry, And generating a cache, wherein step (b) includes a corresponding entry corresponding to a target IP packet in which an error is detected, for IP packets having the same address information among the IP packets in which an error is detected. By reference, it is characterized in that the execution.

Further, the step (b) may include: (b2) retrieving the corresponding entry from the cache, (b3) determining the state of each field of the corresponding entry, and (b4) the step (b3) If it is determined that the continuous error occurrence condition has exceeded the predetermined number of times, setting and subtracting the second timer field of the corresponding entry to the second predetermined time; and (b5) the second step in the step (b3). If it is determined that the second predetermined time set in the timer field has not elapsed, it is preferable to further include the step of not transmitting the ICMP packet to the transmitting node of the target IP packet.

In addition, (b6) if the search fails in the step (b2) may further comprise the step of generating a new entry corresponding to the target IP packet.

In addition, if it is determined in step (b6) that the first timer field of the corresponding entry is 0 in step (b3), the method may further include deleting the corresponding entry.

The method may further include setting and subtracting the first timer field to the first predetermined time when it is determined that the first timer field of the corresponding entry is 0 in step (b6).

In the step (b3), the states of the second timer field, the first timer field, and the error count field of the corresponding entry may be sequentially determined. In this case, (b6) the corresponding entry in the step (b3). If the second timer field of is 0, the first timer field is not 0, and it is determined that the error count field has not reached the predetermined number of times, the error count field of the corresponding entry is incremented by one. The method may further include setting and subtracting the first timer field to the first predetermined time.

In addition, the entry may further include a valid bit field for indicating whether or not the entry is used, wherein the entry includes an ICMP type defined in the ICMP protocol for transmitting an ICMP packet to a transmitting node of an IP packet in which an error is detected. It may further include an ICMP type field and an ICMP code field for indicating an ICMP code, respectively, wherein the address information field includes a source address field and a destination for respectively indicating source address information and destination address information of an IP packet in which an error is detected. It is characterized by consisting of an address field.

Also, the step (b) increases the error count field of the corresponding entry by 1 each time the next error is detected while the previous error is detected and the first timer field of the corresponding entry is not zero. The first timer field is set to the first predetermined time and subtracted, and when the error count field exceeds the predetermined number of times, the second timer field of the corresponding entry is set to the second predetermined time and subtracted. If an error is detected in the target IP packet received while the second timer field is not 0, the ICMP packet for the error is not transmitted to the transmitting node of the target IP packet.

In addition, to achieve the above object, the present invention provides a method for processing an error of IP packets received from at least one transmitting node, comprising the steps of: (a) detecting an error in the received IP packets; (b) disconnecting communication with the transmitting node of the detected IP packets for a second predetermined time when an error is detected more than a predetermined number of times for the first predetermined time. An IP packet error processing method is provided.

In addition, in order to achieve the above object, the present invention provides a computer-readable recording medium having recorded thereon a program for executing a method for processing an error of IP packets received from at least one transmitting node. (a) detecting an error in the received IP packets; and (b) for an IP packet in which an error is detected, a situation in which a next error is detected within a first predetermined time from when a previous error is detected is predetermined. And if the number of times is exceeded, disconnecting communication with the transmitting node of the IP packets for which an error is detected for a second predetermined time.

In addition, in order to achieve the above object, the present invention provides a computer-readable recording medium having recorded thereon a program for executing a method for processing an error of IP packets received from at least one transmitting node. (a) detecting an error in the received IP packets; and (b) for an IP packet in which an error is detected, when an error is detected more than a predetermined number of times during a first predetermined time. And disconnecting the communication with the transmitting node of the packets for a second predetermined time.                     

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

4 shows an error processing apparatus according to a preferred embodiment of the present invention. The error processing apparatus 40 according to the present embodiment includes an error detector 42, a cache 44, and an error processor 46. In addition, the error processing apparatus 40 may be implemented in a one-chip form inside the receiving node 30, and the receiving node 30 includes a router for establishing a communication path. .

The error detector 42 detects an error of the plurality of IP packets received from the at least one transmitting node 20 and transmits the result along with the corresponding IP packet to the error processor 46. Error detection includes error detection of each field of the header of the IP packet along with errors such as Unreachable Destination, Packet Too Big, and Time Exceeded. In addition, an error of each field of the header of the IP packet includes a version error of the IP packet, a payload length error, an unrecognized next header error, and the like.

The cache unit 44 is composed of one or more entries including a plurality of fields indicating error related information of an IP packet in which an error is detected, and provides information necessary for the error processing unit 46 to perform error processing.

An example of the configuration of an entry is shown in FIG. An entry is used to set a valid bit field (Valid) for indicating whether the entry is used or 1, an error count field (Err_cnt) for counting the number of error detections, and a maximum error detection wait time to subtract by unit time. A first timer field, a second timer field for setting a maximum communication disconnection time to subtract by unit time, and an address information field indicating address information of an IP packet in which an error is detected (Source Address: SA, Destination Address: DA) It includes.

In this case, according to FIG. 5, the entry includes the source address information field SA and the destination address information field DA, but if the receiving node 30 has only a single global address, the entry has a destination address in the entry. The field DA may be omitted. In addition, the valid bit field (Valid) is a field that is referred to to perform the search only for the entry being used in the entry search process to be described later, the valid bit field (Valid) may be omitted from the entry, depending on the performance of the system. On the other hand, although not shown in Figure 5, ICMP error type and ICMP error code defined in the ICMP protocol for reference when generating an ICMP packet and transmitting to the transmitting node 20 for the IP packet detected an error in the error processing process An ICMP error type field and an ICMP error code field may be added to the entry.

The error processing unit 46 refers to the cache unit 44 according to the error detection result from the error detection unit 42, deletes or updates the corresponding entry, discards the corresponding IP packet, normally processes the corresponding IP packet, or ICMP. A packet is generated and transmitted to the transmitting node 20. More specifically, the error processing unit 46 has a situation in which the next error is detected within the maximum error detection waiting time from when the previous error is detected for the target IP packets having the same address information among the IP packets in which the error is detected. In the case where the maximum error allowable number is continuously generated, the error processing is performed by disconnecting the communication with the transmission node of the target IP packets for the maximum communication disconnection time. At this time, the same address information implies that the source address information and the destination address information included in the header of the IP packets are the same.

6 is a time flowchart for explaining an error processing operation of the error processing unit 46. At this time, it is assumed that the maximum number of error allowances (Ecm) is five. When an error is initially detected at time T1, the error processing unit 16 sets the error count field Err_cnt to 1 and sets the first timer field Timer A to the maximum error detection waiting time Ta so that the unit time is determined. Subtract by When the second error is detected at time T2 within the maximum error detection wait time Ta from the point T1, the error processing unit 46 increments the error count field Err_cnt by 1 and increases the first timer field Timer A to the maximum error. It resets to the detection waiting time Ta and subtracts by unit time. Since the sixth error exceeding the maximum number of error allowances (Ecm = 5) within the maximum error detection waiting time Ta from the time T5 has occurred at the time T6, the error processing section 46 is now during the maximum communication disconnection time Tb. Disconnect from communication with the sending node.

On the other hand, the error processing section 46 transmits a corresponding ICMP packet to the transmitting node 20 whenever an error is detected with respect to an error generated before the communication disconnection, thereby causing the transmitting node 20 to take an appropriate action on the error. To help. For example, when a predetermined number of ICMP packets are received from the receiving node 30 within a predetermined time, it may be considered that there is a malicious attack on the IP packet, and appropriate measures such as finding another router path may be taken.                     

In addition, the communication disconnection includes discarding the IP packet without receiving the IP packet from the transmitting node but transmitting the corresponding ICMP packet to the transmitting node 20 even if an error is detected in the IP packet during the communication disconnection time. Therefore, the network load of the receiving node can be reduced by preventing the abuse of ICMP packet transmission for the occurrence of abnormal IP packet error.

In FIG. 7, an error processing device 40 including the detailed configuration of the error processing unit 46 of FIG. 4 is illustrated. The error processing unit 46 includes an entry searching unit 462, an entry processing unit 464, a field determining unit 466, and a packet processing unit 468. At this time, if the error detection is successful, the error detection unit 42 transmits the address information of the IP packet in which the error is detected, along with the error detection signal, to the entry retrieval unit 162, and transmits the IP packet to the packet processing unit 468. To pass. If the error detection unit 42 does not detect an error, the error detection unit 42 transfers the corresponding IP packet to the packet processing unit 468 together with an error detection failure signal.

The entry retrieval unit 462 receives the address information of the IP packet in which the error is detected together with the error detection signal from the error detection unit 12 and stores an entry including an address information field indicating the same address information as the corresponding IP packet. In step 44, if the search is successful, the entry is transmitted to the field search unit 466. If the search fails, the entry generation request signal is transmitted to the entry processing unit 464.

The entry processing unit 464 generates a new entry in accordance with the entry generation request signal received from the entry search unit 462, stores the new entry in the cache unit 44, and deletes the entry according to the search result of the field determination unit 466. Or an ICMP packet transmission request signal to the packet processing unit 468.

The field determining unit 466 determines whether each field of the corresponding entry received from the entry searching unit 462 satisfies a predetermined condition, and transmits a packet discard request signal to the packet processing unit 168 according to the determination result, or the entry processing unit 164. Transmits an entry processing request signal.

The packet processor 468 generates an ICMP packet for the corresponding error according to the ICMP packet transmission request signal received from the entry processor 464, and transmits the ICMP packet to the transmitting node 20, and discards the packet received from the field discriminator 466. According to the request signal, the corresponding IP packet is discarded and no separate ICMP packet is generated. At this time, the packet processing unit 468 may generate an ICMP packet by referring to the corresponding IP packet received from the error detection unit 42. In addition, the packet processing unit 468 performs normal processing on the IP packet based on the normal processing request signal received from the error detection unit 42. At this time, the normal processing for the IP packet includes transferring the upper layer data (eg, TCP data) of the IP packet to the upper layer (eg, the TCP layer in the OSI 7 layer).

The operation of the error processing device 40 of FIG. 7 will be described below.

When the receiving node 30 receives the IP packet from the transmitting node 20, the error detecting unit 42 detects an error in the received IP packet, and if the error is not detected, delivers the corresponding IP packet to the packet processing unit 468. The packet processing unit 468 processes the corresponding IP packet normally and waits for the next packet.

When the error detector 42 detects an error in the received IP packet, the address information of the IP packet is transferred to the error processor 46, and the entry search unit 462 of the error processor 46 sends the IP packet. The cache unit 44 searches for the target entry having the same address information as that, and transfers the target entry to the field determination unit 466. If the search fails, the entry generation request signal is sent with the address information of the corresponding IP packet. Forward to 464. The entry processing unit 464 sets the valid bit field Valid of the entry to 1, sets the error count field Err_cnt to 1 according to the entry generation request signal, and detects the maximum error of the first timer field Timer A. Set the waiting time Ta and subtract by unit time, set the second timer field Timer B to 0, and set the source address field SA and the destination address field DA as address information of the corresponding IP packet, respectively. Set it.

The field discrimination unit 466 determines whether the second timer field Timer B of the corresponding entry is 0. If the communication is not appropriate because the maximum communication disconnection time has not yet passed, the packet processing unit 468 Discards the IP packet and waits for receipt of the next IP packet. At this time, the packet processing unit 468 does not transmit the ICMP packet to the transmitting node of the IP packet. On the other hand, if the second timer field Timer B is 0, it is determined whether the first timer field Timer A is 0. If 0, that is, a previous error is detected and the maximum error detection wait time has already passed. In this case, the target entry is deleted, and the packet processing unit 468 generates an ICMP packet for the corresponding error and transmits it to the transmitting node 20. When the first timer field Timer A is not 0, it is determined whether the error count field Err_cnt is equal to the maximum number of error allowances. Set the second timer field (Timer B) of the target entry to the maximum communication disconnection time (Tb) and subtract by unit time, set the error count field (Err_cnt) to 0, and set the first timer field (Timer A) to 0. Is set to any value, for example, the maximum error detection waiting time Ta. On the other hand, when the error count field Err_cnt has not yet reached the maximum number of error allowances, the error count field Err_cnt of the target entry is increased by one, and the first timer field Timer A is set to the maximum error detection wait time ( Ta) to subtract by unit time.

In this way, the error processing apparatus 40 disconnects the maximum communication when the error detected within the maximum error detection waiting time Ta is continuously exceeded the maximum error allowable number Ecm since the previous error is detected. Discarding communication with the transmitting node by discarding the IP packet where an error was detected during the time Tb and not generating an ICMP packet. In addition, when no error is detected within the maximum error detection waiting time Ta, the entry is deleted in consideration that there is no possibility of abnormal error occurring in the corresponding IP packet.

On the other hand, although the target entry was deleted when no error was detected within the maximum error detection wait time Ta, the first timer field of the target entry ( By resetting and subtracting Timer A) to the maximum error detection wait time Ta and setting the error count field Err_cnt to 0, a new error is detected when an IP packet having the same address information as the target entry is subsequently detected. You can use existing entries without having to create them.

In addition, in the present embodiment, the error processing is performed by referring to the cache unit so as to disconnect the communication only to the transmitting node in question, but for a plurality of IP packets in consideration of indiscriminate packet manipulation or DoS attack throughout the network. If the situation where the next error is detected exceeds a predetermined number of times within the first predetermined time from when the previous error is detected, the error processing unit may disconnect the communication for the second predetermined time for all transmitting nodes connected to the receiving node. It may also be configured, in which case there is no need to provide a separate cache.

Hereinafter, an error processing method according to a preferred embodiment of the present invention will be described with reference to FIG. 8.

In step S801, an IP packet is received from the transmitting node 20. In step S803, it is determined whether an error is detected in the received IP packet. If no error is detected, the process proceeds to step S805, where the IP packet is processed normally and the error processing is completed.

If an error is detected in step S803, the flow advances to step S807, where a next error is detected within a maximum error detection waiting time from when a previous error is detected for a plurality of target IP packets having the same address information. If the maximum number of error allowances is exceeded, it is determined whether or not it has been continuously generated. If the maximum number of error allowances is exceeded, the process proceeds to step S809 where the communication with the transmitting node of the target IP packet is disconnected during the maximum communication disconnection time. . In this case, the disconnection of the target IP packet with the transmitting node also includes receiving the IP packet from the transmitting node but discarding the IP packet without transmitting the ICMP packet to the transmitting node during the communication disconnection time. On the other hand, if it is determined in step S807 that the maximum number of error allowances has not been exceeded, the flow advances to step S811 to generate an ICMP packet for the corresponding error and transmits it to the transmitting node.

9 is a detailed flowchart of the error processing method of FIG. 8. Meanwhile, in order to perform the error processing method of FIG. 8 with respect to IP packets having the same address information among the IP packets in which an error is detected, an error processing method according to an exemplary embodiment of the present invention may be performed at the time of communication start or initial error detection. And generating a cache. The cache consists of at least one entry as shown in Fig. 5, each entry being identified with each other by the address information in the address information field.

When receiving an IP packet from the transmitting node in step S901, in step S903 it is determined whether an error is detected in the received IP packet. If no error is detected, the IP packet is processed normally in step S905 and the next IP packet is received. Wait for reception.

In step S907, it is searched whether an entry including the same information as the address information of the received IP packet exists in the cache. If there is no entry in step S907, the flow advances to step S909 to create a new entry for the corresponding IP packet and initialize each field. Initialization subtracts unit time by setting the valid bit field Valid to 1, the error count field Err_cnt to 1, and setting the first timer field Timer A to the maximum error detection wait time Ta. And setting the second timer field Timer B to 0 and setting the source address field SA and the destination address field DA to the source address information and the destination address information of the corresponding IP packet, respectively. Subsequently, in step S925, an ICMP packet is created, transmitted to the transmitting node, and waits for reception of the next IP packet.

If the corresponding entry exists in step S907, the flow advances to step S911 to determine whether the second timer field Timer B of the entry is zero. If the second timer field is not 0 in step S911, since the maximum communication disconnection time Tb has not yet passed, in step S913, the corresponding IP packet is discarded and the next IP packet is waited for.

If the second timer field Timer B is 0 in step S911, the flow advances to step S915 to determine whether the first timer field Timer A is zero. If the first timer field Timer A is 0 in step S915, the flow advances to step S917 to delete the corresponding entry, and then transmits an ICMP packet to the transmitting node in step S927.

If the first timer field Timer A is not 0 in step S915, the flow proceeds to step S919 to determine whether the error count field Err_cnt has reached the maximum number of error allowances Ecm. If Err_cnt = Ecm in step S919, the flow advances to step S921 to update the entry and wait for reception of the next IP packet. At this time, in step S921, the second timer field Timer B is set to the maximum communication disconnection time Tb and subtracted by unit time, the error count field Err_cnt is set to 0, and the first timer field ( Set Timer A) to any non-zero value such as the maximum error detection wait time Ta.

If Err_cnt ≠ Ecm in step S919, the process proceeds to step S923 to update the entry, and then in step S925, ICMP packets are transmitted to the transmitting node. At this time, in step S923, the error count field Err_cnt is increased by 1, and the first timer field Timer A is reset to the maximum error detection wait time Ta and subtracted by unit time.

10 is a conceptual diagram for explaining the process of implementing the error processing method of this embodiment in more detail. At this time, it is assumed that the maximum number of error allowances Ecm is 5, the maximum error detection wait time Ta is 10 seconds, and the maximum communication disconnection time Tb is 30 seconds. In addition, for convenience of description, it is assumed that all IP packets received at the receiving node belong to the same entry, and thus, the source address field and the destination address field are omitted in the drawing. In addition, it is assumed that an error is detected in all received packets.

If the first error packet P1 is received, there will be no entry to which the packet P1 belongs, so in step S1009 a new entry En is created and a valid bit field Valid, an error count field Err_cnt, a first timer field ( Timer A) and the second timer field Timer B are set to (1, 1, 10, 0).

If the error packet P2 is received 3 seconds after the error packet P1 is received, the entry En is in a state of (1, 1, 7, 0), and therefore, in step S1023, the entry En is (1, 2, 10, 0). Is updated to). When the error packet P3 is received 5 seconds after the error packet P2 is received, the entry En is in a state of (1, 2, 5, 0), and therefore, in step S1023, the entry En is (1, 3, 10, 0). Is updated to). The error count field Err_cnt is incremented by 1 at step S1023 because an error has been detected for the error packets P4 and P5 within 10 seconds, which is the maximum error detection waiting time from the time when the previous error occurred.

If the error packet P6 is received 6 seconds after the error detection time of P5, the entry En is in the state of (1, 5, 4, 0), so that the value of the error count field Err_cnt is 5 in step S1019. The entry En is set to (1, 0, 10, 30) in step S1021 by matching with the maximum number of error allowances. Therefore, the error packet P7 is discarded in step S1013 because the error packet P7 was received within 30 seconds, which is the maximum communication disconnection time after the error packet P6 was received.

Since the error packet P8 was received after 30 seconds, which is the maximum communication disconnection time, the entry En is set to (1, 1, 10, 0) in step S1023. Also, since the error packet P9 was received 15 seconds after the error packet P8 was received, the error packet P9 exceeded the maximum error detection waiting time of 10 seconds. Therefore, when the error packet P9 is received, the entry En is in the state of (1, 1, 0, 0), so the entry En is deleted in step S1017.

In the above, the method according to the preferred embodiment of the present invention has been described as being implemented by using the error processing device 40. However, the method is performed in a receiving node by a computer program consisting of a set of codes for instructing a computer. It can also be executed in software. Accordingly, the scope of the present invention includes a computer-readable recording medium which records a program for executing the method of the present invention.

In addition, it should be understood that various modifications may be made to the preferred embodiment of the present invention within the scope of the technical idea of the present invention. For example, in the preferred embodiment of the present invention, the communication with the transmitting node is disconnected for the second predetermined time when the situation where the error is detected within the first predetermined time after the previous error is detected a predetermined number of times in succession. In some cases, when an error more than a predetermined number of times is detected during the first predetermined time, communication with the transmitting node may be disconnected for the second predetermined time. Accordingly, the scope of the claims appended hereto is not limited by the preferred embodiments of the invention described above.

According to the present invention, when an error of an IP packet detected within a predetermined time occurs continuously over a predetermined number of times, there is an effect that the network load of the receiving node can be reduced by not transmitting the ICMP packet to the transmitting node.

In addition, according to the present invention, if an error detected within a predetermined time for the IP packets having the same source address occurs more than a predetermined number of times in succession, the ICMP packet is not transmitted to the transmitting node of the IP packet in question. There is an effect that can reduce the network load of the receiving node and increase the communication efficiency.

Claims (20)

An apparatus for processing an error of IP packets received from at least one transmitting node, the apparatus comprising: An error detector for detecting an error in the received IP packets; For IP packets in which an error is detected, ICMP to the transmitting node of the detected IP packets when an error has occurred more than a predetermined number of times when the next error is detected within a first predetermined time from when a previous error is detected. An error processing unit which disconnects communication with the transmitting node for a second predetermined time by stopping the transmission of the packet, and transmits a corresponding ICMP packet to the transmitting node whenever an error is detected for an error that occurred before the communication disconnection. IP packet error processing apparatus comprising a. 2. The apparatus of claim 1, wherein the error processing unit performs the error processing on IP packets having the same address information among the IP packets in which an error is detected. An apparatus for processing an error of IP packets received from at least one transmitting node, the apparatus comprising: An error detector for detecting an error in the received IP packets; For the IP packets in which an error is detected, if an error is detected more than a predetermined number of times during the first predetermined time, for a second predetermined time by stopping transmission of the ICMP packet to the transmitting node of the detected IP packets. And an error processing unit which disconnects communication with the transmitting node and transmits a corresponding ICMP packet to the transmitting node whenever an error is detected with respect to an error generated before the disconnection of the communication. A method for handling errors in IP packets received from at least one transmitting node, the method comprising: (a) detecting an error in the received IP packets; (b) For the IP packets for which an error is detected, the transmitting node of the IP packets for which an error is detected when a situation in which the next error is detected exceeds a predetermined number within a first predetermined time from when a previous error is detected. Interrupting communication with the transmitting node for a second predetermined time by stopping transmission of the ICMP packet to the network, and sending a corresponding ICMP packet to the transmitting node each time an error is detected for an error that occurred before the communication disconnection. IP packet error processing method comprising the step of. 5. The method of claim 4, wherein step (b) is performed on IP packets having the same address information among the IP packets in which an error is detected. 5. The method of claim 4, further comprising: (c) processing the received IP packets normally when no error is detected in step (a). The method of claim 4, wherein step (b) comprises: (b1) a first timer field for setting and subtracting the first predetermined time, a second timer field for setting and subtracting the second predetermined time, At least one entry including an error count field for counting a situation where a next error is detected within a first predetermined time from when a previous error was detected, and an address information field for indicating address information of an IP packet in which the error was detected Wherein the IP packets having the same address information correspond to the same entry, further comprising: generating a cache; The step (b) is performed on the IP packets having the same address information among the IP packets in which an error is detected, with reference to a corresponding entry corresponding to the target IP packet in which the error is detected. How to handle errors. The method of claim 7, wherein step (b), (b2) retrieving the corresponding entry from the cache; (b3) determining the states of each field of the corresponding entry; (b4) If it is determined in step (b3) that the next error is detected within the first predetermined time from when the previous error is detected, the second timer field of the corresponding entry is determined. Setting and subtracting the predetermined time; (b5) if it is determined in step (b3) that the second predetermined time set in the second timer field has not elapsed, further comprising not transmitting an ICMP packet to a transmitting node of the target IP packet. IP packet error processing method. 9. The method of claim 8, further comprising: (b6) generating a new entry corresponding to the target IP packet when the search fails in the step (b2). 9. The method of claim 8, further comprising: (b6) deleting the corresponding entry when it is determined in step (b3) that the first timer field of the corresponding entry is zero. 9. The method of claim 8, further comprising: setting and subtracting the first timer field to the first predetermined time when it is determined in step (b6) that the first timer field of the corresponding entry is 0 in step (b3). IP packet error handling method. 9. The method of claim 8, wherein step (b3) sequentially determines states of a second timer field, a first timer field, and an error count field of the corresponding entry. 13. The method of claim 12, wherein (b6) the second timer field of the corresponding entry is zero, the first timer field is not zero, and the error count field has not reached the predetermined number of times in step (b3). And if determined, incrementing the error count field of the corresponding entry by one and setting and subtracting the first timer field to the first predetermined time. 8. The method of claim 7, wherein the entry further comprises a valid bit field for indicating whether an entry is used. 10. The ICMP code field of claim 7, wherein the entry further includes an ICMP type field and an ICMP code field for respectively indicating an ICMP type and an ICMP code defined in the ICMP protocol for transmitting an ICMP packet to a transmitting node of an IP packet in which an error is detected. IP packet error processing method characterized in that. 8. The method of claim 7, wherein the address information field comprises a source address field and a destination address field for indicating source address information and destination address information of an IP packet in which an error is detected. 8. The method according to claim 7, wherein the step (b) includes the error count field of the corresponding entry whenever the next error is detected while the previous error is detected and the first timer field of the corresponding entry is not zero. Increment the first timer field at the same time as the first predetermined time and increase by one, and if the error count field exceeds the predetermined number of times, subtract the second timer field of the corresponding entry to the second predetermined time. And subtract the ICMP packet for the error to the transmitting node of the target IP packet when an error is detected in the target IP packet received while the second timer field is not 0. IP packet error handling method. A method for handling errors in IP packets received from at least one transmitting node, the method comprising: (a) detecting an error in the received IP packets; (b) for the IP packets for which an error is detected, if an error is detected for a predetermined number of times or more during the first predetermined time, by stopping the transmission of the ICMP packet to the transmitting node of the IP packets for which the error is detected; Disconnecting communication with the transmitting node for a predetermined time, and transmitting a corresponding ICMP packet to the transmitting node whenever an error is detected for an error that occurred before the disconnection of the communication. A computer-readable recording medium having recorded thereon a program for executing a method for processing an error of IP packets received from at least one transmitting node, the method comprising: (a) detecting an error in the received IP packets; (b) For the IP packets for which an error is detected, the transmitting node of the IP packets for which an error is detected when a situation in which the next error is detected exceeds a predetermined number within a first predetermined time from when a previous error is detected. Interrupting communication with the transmitting node for a second predetermined time by stopping transmission of the ICMP packet to the network, and sending a corresponding ICMP packet to the transmitting node each time an error is detected for an error that occurred before the communication disconnection. And a recording medium. A computer-readable recording medium having recorded thereon a program for executing a method for processing an error of IP packets received from at least one transmitting node, the method comprising: (a) detecting an error in the received IP packets; (b) for the IP packets for which an error is detected, if an error is detected for a predetermined number of times or more during the first predetermined time, by stopping the transmission of the ICMP packet to the transmitting node of the IP packets for which the error is detected; Disconnecting communication with the transmitting node for a predetermined time, and transmitting a corresponding ICMP packet to the transmitting node whenever an error is detected for an error that occurred before the disconnection of the communication.

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